The present invention relates to a method and composition for creating a barrier for environmental control and protection. In one aspect of the invention, a barrier is provided for controlling vegetation. In another aspect of the invention, a barrier is provided for protecting concrete from acid attack and deterioration. In a further aspect of the invention, a barrier is provided for the protection of underground or partially underground structures, such as cable, pipelines, and metal or concrete tanks to guard against leakage.
In the landscaping of homes, office parks and golf courses, it is frequently desirable and necessary to control vegetation. For example, there is a need to separate flower beds from grassy areas in order to control invasion of the flower beds by grasses. For golf courses, greens are planted with a different grass than the surrounding area and it would be helpful to prevent invasion by undesirable grass species into the green area. Also, there is a problem with moles burrowing into the green. Therefore, a need exists to control vegetation and/or restrain undesirable vegetation and pests in certain well defined areas.
Furthermore, there exists a need for protecting concrete surfaces from acid-caused effects. The problem of acid rain not only attacks trees but causes problems for concrete also. Acid build-up in the soil can attack or deteriorate concrete structures such as roadways, airport runways, concrete buildings and the like.
This invention also relates to a method and composition for creating a protective barrier to protect various structures against attack by insects, humidity and fungi. More particularly, the present invention relates to compositions and methods to protect wooden structures from termites and other wood-decaying injurious insects.
All types of wooden structures, and in particular wooden houses, are subject to being exposed to the action of humidity in the atmosphere and, depending on location, to dampness or water seepage. This creates an ideal atmosphere for growth of fungi such as mildew and the like. When wooden structures are attacked by wood-decaying fungi, they can be seriously damaged, especially when the foundation that supports the structure and stability of the house is attacked. The deterioration of wooden structures by the action of humidity and by the biological attackers are inter-related, because wood-decaying fungi and termites thrive and proliferate under humid conditions, such as are found under the floors of homes where water evaporates from the ground surface.
It is, therefore, very important to protect the wood materials employed for house construction and wooden houses and structures from the action of humidity, fungi, insects and other biological attacks in one convenient procedure.
Heretofore, proposals have been made to prevent the action of humidity from the ground surface and to control the biological attacks. For example, it has been suggested to cover the ground surface with polyethylene sheets in order to cut off humidity therefrom. Likewise, it has been proposed to cover the ground surface with sheets, called "termite-controlling sheets," in order to attain various objects, such as prevention of exposure to humidity, for wood preservation and for termite control at the same time.
However, these methods have occasioned a number of drawbacks. For instances, it is a labor intensive effort to spread sheets on a ground surface in a satisfactory manner. It is necessary to first cut sheets to adapt them to irregularly shaped foundations; in order to reduce the tendency to cause gaps thereby leading to imperfect prevention against humidity and moisture.
It has also been proposed in the past to spray a variety of synthetic resin-containing liquid preparations, which can contain active ingredients such as termite-controlling agents and/or wood preservative agents, on the ground surface under the wooden structure. However, these methods also were not totally successful. For example, the synthetic resin liquid preparations tend to penetrate into the soil before a dried film is formed on the soil surface. Hence, a much larger quantity of the liquid is required in order to attain the desired object of adequate protection. Further, as the soil surface is usually uneven, mounded parts may not be sufficiently treated with the liquid and, as the result, a uniform film may not be formed on the whole surface of the soil. This results in imperfect moisture and insect resistance and poor wood-preservative effects.
In conventional termite control methods for wooden structures, insect control chemicals containing emulsions or liquid concentrates are sprayed on the under floor soil and on the supporting members for such structures. These methods, however, do not permanently immobilize the insect control chemicals and do not provide prolonged insect control effects because the insect control ingredients evaporate in a relatively short time period. In order to improve permanent immobilization, certain insect control methods have been developed. For instance, in one method a hardened resin foam coated isolation layer containing an insect control chemical is formed by forcefully mixing a main solution (the asphalt emulsion modified polyvinyl acetate resin emulsion, which is a mixture of polyvinyl acetate resin emulsion and asphalt emulsifiable concentrates at about 7:3 proportion) containing an insect control chemical and an organic solvent solution (in which hydrophilic low molecular weight polyurethane resin is dissolved by methyl ethyl ketone or other organic solvents). The mixture is then sprayed on the structure's under floor soil surface.
Asphalt emulsion concentrate is a highly viscous black colored material and asphalt emulsion modified polyvinyl acetate resin is also black. The equipment and tools for spraying this mixture are quickly blackened and dirtied. Operators must be extremely careful when handling and spraying the mixture because their work clothes cannot be cleaned completely if soiled by the mixture. Therefore, work efficiency is significantly reduced. Asphalt emulsion concentrate, because it is usually a cationic surface active agent-based, oil-in-water type emulsion formula, is susceptible to emulsion destruction when in contact with an anionic surface active agent. Therefore, condensation and separation of emulsified-dispersed asphalt can occur. Thus, it significantly restricts the choice of emulsion concentrate used for aqueous polyvinyl acetate resin emulsion. In addition, asphalt is principally composed of hydrocarbons and thus dissolves rubber gaskets and other materials used in the spraying equipment and tools. In addition, polyvinyl acetate emulsion containing added asphalt increases the viscosity of the emulsion, thus making handling more difficult.
The mixed resin foam coating layer formed by mechanically and forcefully mixing the asphalt emulsion modified polyvinyl acetate resin and the organic solvent solution of hydrophilic polyurethane resin and then spraying the resulting formulation embeds and immobilizes the insect control ingredient which is mixed in and sprayed together with the other ingredients. However, the dried coating layer formed thereby gradually contracts over time with the result that an undetermined amount of cracks and gaps appears several years later. The performance of the coating layer at that point is significantly reduced and the insect control effects are greatly diminished.
An object of the present invention is to avoid the defects of the conventional methods as have been described above and as known in the art. Another object of the present invention is to improve the protection of wood materials used in the construction of housing and of wooden structures against moisture, fungi and insect damage.
Another object of this invention is to provide a protective barrier layer that has the flexibility and other properties to prevent cracks in the layer over time, and which is physically stable enough to practically isolate a structure, such as the under floor space of a building from the soil surface over a long time period.
Another object of the invention is to provide an under floor insect control method that has superior operability and easier handling.
A still further object of the invention is to provide a practical and desirable insect control buffer or barrier layer that can keep the insect control chemical ingredients immobilized in a stable condition over a long time period and eliminate chances of termites or other microorganisms eating through and surfacing above the buffer layer.
Yet another object of the present invention is to achieve a superior system for environmental control and protection.